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对ZG40Cr25Ni20耐热铸钢和节镍经济型双相耐热铸钢进行恒温氧化实验,得到了两种材料的氧化动力学行为曲线,结合扫描电镜、能谱分析仪及X射线衍射等手段研究了高温抗氧化的差异,并探究了高温氧化的微观机理。结果表明,节镍经济型耐热铸钢虽然降低了Ni的含量,但是增加Cr和Mn能在氧化层的外层形成稳定的保护型氧化膜Cr_2O_3,一定程度上阻挡了金属阳离子的向外扩散和O离子的向内扩散,使其氧化激活能由148.4 k J·mol~(-1)提高至245.7 k J·mol~(-1),从而降低了氧化速率,改善了材料的高温抗氧化性能。
The oxidation kinetics of ZG40Cr25Ni20 heat-resistant cast steel and economy nickel heat-resistant dual-phase heat-resistant cast steel were investigated. The oxidation kinetics curves of the two materials were obtained. Combining with scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction, The difference of high temperature oxidation resistance, and explores the microscopic mechanism of high temperature oxidation. The results show that economically heat-resistant cast steel with nodular nickel reduces the content of Ni, but adding Cr and Mn can form a stable protective oxide film Cr_2O_3 on the outer layer of the oxide layer to a certain extent, blocking the outward diffusion of metal cations And O ions, the oxidation activation energy was increased from 148.4 kJ · mol -1 to 245.7 k J · mol -1, thereby reducing the oxidation rate and improving the high temperature oxidation resistance of the material performance.